Why are some people protected from Covid-19 without having contracted the disease? - EL PAÍS in English

For now, the authors of the study, researchers from La Jolla Institute for Immunology in the United States, acknowledge that it is “very speculative” to link the better prognosis of some Covid-19 patients with their previous exposure to the coronaviruses that cause the common cold.

“In young people, T cells are more active, but this response starts to decline from the age of 70,” she says.

One of the reasons why coronaviruses can cause colds is that they share a viral spicule protein that is used to colonize host cells.

While the research may explain why young people have less serious cases of Covid-19, it does not explain the gap in the contagion rates between Spain’s 17 regions.

Jesús Rodríguez Baño, the head of infectious disease at the Virgen Macarena hospital in Seville, also backs the hypothesis that people have more immunity to Covid-19 because they have been in contact with similar diseases, but says there still needs to be epidemiological confirmation of the data.

A better understanding of the immunity of a population could shed light on the mysteries that remain about why Covid-19 affects people so differently.